Figure out work-holding for +60

[FlyingLotus1983]

How will the PCB attach to the machine for the demo? It needs to go through these three steps:

• Solder paste
• PnP
• Reflow

[FlyingLotus1983]

Blocking this issue is that we're waiting on the new reflow / preheat controller to get here (the flat heated surface one). Need to try it out and reflow a board before this issue can continue.

[FlyingLotus1983]

200mm x 200mm hotplate showed up today.

@vonnieda , @itsmefelix- , and myself investigated a few options with how to mount it to the machine, and came up with the following:

• Drill 4 holes in the powder-coated steel bed plate (leftover v1 beta test part). (assigned to @WillD77 to come up with printed-out CAD template)
• Mount the current steel bed-plate to the BOTTOM of the horizontal bars, using M4 extrusion nuts. Use 20-25mm brass standoffs or springs to get the bed 25mm lower. (assigned to @DCSMITH907 )
• Bisect the hot-plate into 2 sections (hotplate and the controller). (assigned to @flyinglotus1983 )
• Lengthen the wires between the two sections. (assigned to @flyinglotus1983 )
• "Hide" the controller off-camera for purposes of the video. Later on, we'll make a custom board for this.
• Screw the hotplate section directly on the steel plate, using included hardware. Use insulation to keep the steel plate from getting too hot (assigned to @DCSMITH907 )
• Mount the PCB clamp (from the PCB preheater) to the frame's bottom extrusions, using M4 hardware. (assigned to @DCSMITH907 )
• Purchase some longer 6mm smooth rods ( assigned to @itsmefelix- )
• Assemble the PCB clamp onto the frame, above the heated bed. (assigned to @DCSMITH907 )

The strategy is to place the board while it's in the clamp(s). Then remove the PCB from the clamps and set the PCB down onto the heater.

We'll leave this issue open until it's built and we see how well it works.

[FlyingLotus1983]

The +60 prototype bed system works pretty well and will get us through the demo. Closing this issue for now as it only pertains to +60. I created a separate issue for heated bed DFM ( Issue #38 ), all comments / questions pertaining to DFM of heated bed and work-holding should be discussed there..